(9.45 MB) Download The Vigilante Group Of New Yorkers Who Hunt Rats At Night (HBO)

Rats aren't only a part of New York City’s underground — they're an inseparable part of its pop culture. There’s Master Splinter from the Ninja Turtles, Pizza Rat, and even Cannibal Rat. But for every celebrity rat, there’s another 250,000 to 2 million anonymous rodents living in the city — and the city health department is fighting to bring down.

The battle can be deadly. Last year, three people in a Bronx city block contracted leptospirosis through rat urine. Only two survived.

To combat the problem, Mayor Bill de Blasio launched a $32 million initiative to rid New York of its signature rodents, concentrating on hyper-infested areas that the city describes as "rat reservoirs."

Multiple city agencies are currently focusing their efforts around public housing buildings, where they plan to replace dirt basement floors, block passageways and amp up trapping, baiting and poisoning efforts.They also apply dry ice to the rats’ burrow systems, effectively suffocating them as the carbon dioxide gets released while the ice melts.

But if all else fails, a small group of dedicated rat hunters are ready to step in.

When dusk settles, Richard Reynolds and his vigilante rat hunters known as “The Ryders Alley Trencher-Fed Society” — or R.A.T.S for short — roam lower Manhattan’s streets and dumpsters, keeping their dogs’ instincts sharp and the hunting tradition alive.

In the three decades Richard has been hunting rats with his dogs, he says he must have killed thousands of rats. But he doesn’t really keep track.